On estimating the cost of development to the customer, the ratio of testing is a lot, and it is very hard to estimate it. But by automating the testing process, we can estimate the cost, which is near from actual cost.

That is because we can estimate the cost of writing test driver. And if we write it at once, we can execute test automatically.

The rich UI application is hard to do automatic test, but now I'm going to try it. I'll add contents about test at "Software test" in my website.